Foldable valances have heretofore been made having a front panel and return panels with mitered corners and with hinges connecting the return panels to the front panel to allow the return panels to be folded to positions alongside the rear of the front panel for compact packaging and to reduce breakage during storage and shipment. The hingedly connected return panels were adapted to be manually moved into an erected position extending perpendicular to the front panel when the valances were installed. However, the hingedly connected return panels could move out of perpendicularity with the front panel during or after installation and this problem was aggravated when plastic hinges were used. The plastic hinges would take a set once the return panels were folded in overlying relation to the front panels for packaging and such that the plastic hinges would not return toward their original flat conditions sufficient to move and hold the return panels in a fully erect position extending perpendicular to the front panel. This left an objectionable gap at the mitered corner between the return panels and the front panel.